A farmers market in Los Angeles is among more than 8,000 such outlets in the United States offering locally grown food for the burgeoning “locavore” movement. (Getty Images/Dan Porges)

Inspired by a movement that touts healthy eating and warns of danger from an industrialized food supply, millions of Americans are cutting back on processed and fast foods and sugary soda. Many are turning to fresh, lean and “clean” foods out of fear that sugar, salt, fat and additives can lead to heart disease, obesity, diabetes and other problems. Other Americans, however, continue to eat unhealthily, contributing to record levels of diet-related illnesses and rising health care costs. Healthy-eating activists want the government to tax sugary sodas, mandate expanded nutrition labels and restrict portion sizes. The food industry is fighting such proposals, contending that changing the nation's eating habits lies more with the free market than with legislation. Meanwhile, nutritionists and medical professionals are debating the value of gluten-free diets, with proponents claiming that wheat products lead to a wide range of illnesses and critics arguing that the diets lack scientific merit.